EFFECT OF ORGANIC AND INORGANIC NUTRIENT SOURCES ON GROWTH , YIELD AND QUALITY OF RADISH ( Raphanus sativus L . ) VARIETIES IN CHITWAN , NEPAL

A study was conducted in Horticulture farm of Agriculture and Forestry University, Rampur, Chitwan, Nepal, during November 2015 to February 2016 by using three commercial radish varieties (All Season White, Mino Early Long White and Pyuthane Red) and five nutrient sources combination of organic manure (Poultry and Farm yard manure) and recommended dose of inorganic fertilizer (100:80:40 NPK kg ha -1 ) replicated three times in a factorial RCBD design. Most of the plant growth and yield parameters were found superior in treatments consisting poultry manure (PM) alone and in combinations with inorganic fertilizer. Treatment consisting farm yard manure (FYM) was found inferior in most of the cases. At the time of harvest, significantly higher plant height (37.5 cm), number of leaves per plant (24.77), root diameter (39.01 mm), average leaf length (35.03 cm), average leaf width (12.86 cm) was observed in treatment consisting PM (50%) and RDF (50%). Similarly, root yield (73.98 t ha -1 ) and shoot yield (62.52 t ha -1 ) was also found higher in the same treatment. Among the three commercial radish varieties, Mino Early Long White was found superior in most of the growth and yield parameters viz., number of leaves per plant, biological yield, root yield, root length, root diameter, marketable root, smooth root and excellent fleshed root percentage.


INTRODUCTION
Radish (Raphanus sativus L.) is one of the most popular root vegetable of the world which can be grown from tropical to temperate region.It is grown for the consumption of its young fresh tender tuberous root which can be used as cooked or raw food as a salad.It contains good amount of vitamin-C and minerals like P, Ca and K.It also has refreshing and diuretic properties and it can be used in homeopathy for neurological, headache, sleeplessness and chronic diarrhea (Ayub, et al., 2013 andKumar et al., 2014) Radish is one of the most popular root vegetable of Nepal which can be grown in winter season in Terai and throughout the year in hills of Nepal.The popularity of radish cultivation could be due its wider adaptability, low cost of production, short crop duration and can be grown in almost all type of soil without much care.Diseases and pest problems are also less in radish as compare to other vegetable crops (Shrestha and Shakya, 2004).Radish is a short duration and quick growing crop, so, the root growth and development should be uninterrupted.For this, optimum nutrition should be provided through organic, inorganic and bio-fertilizer sources.Chemical fertilizers are expensive and resulted in poor health condition of soil and water if used repeatedly.So, alternative cheap organic sources of nutrients should be used (Kumar et al., 2014).
For the use of organic manure, there are no clear recommendations available.Organic manures differ in their nutrient sources, composition as well as the mineralization rate.So, precise calculation of rate of use is important.Farmers tend to apply either too much or too low organic fertilizers.Due to which soil condition is influenced and amount of nutrients provided by organic manure is either insufficient or over dose for plants (Mbatha, 2008).Appropriate variety selection and use of optimum amount of nutrient is a crucial factor for obtaining higher yield from radish.For the optimum growth of radish roots inside the soil, optimum fertilization with both inorganic and organic sources of nutrient is necessary (Chapagain, et al., 2010).This research work was mainly focus on nutrient management (both organic and inorganic) along with appropriate varietal selection of radish for the late season sowing in Terai condition.

MATERIALS AND METHODS
A study was conducted in Horticulture farm of Agriculture and Forestry University, Rampur, Chitwan, Nepal, during November 2015 to February 2016.The location is inner Terai (plain) area with humid sub-tropical climate.The average temperature during the field research was 20.4 0 C. Rainfall occurred only once during research (7.70mm).The experimental site has acidic soil with low organic matter, low nitrogen and high phosphorus content.
The experiment was carried out in a RCBD with two factors viz.three radish varieties viz., All Season White, Mino Early Long White and Pyuthane Red and five nutrient sources combinations include 100% N through recommended dose of fertilizer (RDF) for radish (100:80:40 NPK ha -1 ) (Anonymous,, 2012), 100% N through PM, 50% N through RDF + 50% N through PM, 100% N through FYM and 50% N through RDF + 50% N through FYM.The FYM and PM used in this experiment were analyzed at Regional Soil Testing Laboratory, Pokhara and the results were found as following.After final field preparation, all the organic manure and chemical fertilizer were applied before sowing and mixed well in soil.Sowing was done at 28 th November, 2015 at the spacing of 40 x 20 cm.Thinning, weeding, hoeing, irrigation and other intercultural operations were done as per recommended.Final harvesting was done 60 days after sowing.Ten sample plants were taken from each plot for data recording during field growth and after harvesting.The observations were recorded during filed growth, canopy height, leaf number, rosette diameter.After harvesting of the crop, root length, diameter, leaf length, width, leaf yield, root and leaf dry weight, harvest index, marketable root, smooth surfaced roots and forked roots percentage were recorded.
All the data were analyzed by using GENSTAT 16 th edition and MS-EXCEL 2010.

Plant height and number of leaves per plant
The individual effects showed significant but interaction between varieties and nutrient sources non-significant on plant height and number of leaves per plant.(Table1).During early growth, varieties did not show any response but at the time of harvest, highest plant height was recorded in Pyuthane Red (36.40 cm).In case of different nutrient sources, the maximum plant height was obtained from N 4 closely followed by N 2 at 25 DAS but at harvest (60DAS) treatment N 3 and N 2 were found similar.No. of leaves showed maximum in N 2 followed by N 4 but no significant difference at except N 4 treatment which produced lower number of leaves/ plant.

Root length, diameter and root yield
The variety Mino Early Long White produced significantly highest root length (23.56 cm) and root yield (74.49 t ha -1 ) but root diameter insignificant.Among the nutrient sources, root length was found insignificant but root diameter showed higher in N 3 followed by N 2 and N 5 .The maximum root yield was obtained from N 3 but at par to N 2 and N 5 , respectively.Root yield was influenced by root length and diameter as well as poultry manure.Farm yard manure and RDF failed to show higher root yield.

Leaf length, width and leaf yield
The Pyuthane Red variety (V 1 ) was produced maximum length of leaf longer (33.9 cm) but at par to V 3 where wider leaves (12.23 cm) from V 3 followed by V 2. (Table 2).Among different nutrient sources, N 3 = PM 50% + RDF 50% produced maximum length (35.03 cm) followed by N 2 and wider leaves (12.86 cm) from N 3 which ultimately resulted maximum leaf yield (62.52 t ha -1 ).The interaction effect of varieties and nutrient sources was found non-significant for leaf length, width and leaf yield.

Dry weight of root and leaf per plant
The variety mino early long white (V 2 ) produced significantly highest root dry weight (15.13 g plant -1 ) and leaf dry weight (12.23 g plant -1 ) as compared to other varieties.Nutrient sources effect was non-significant for root dry weight but in case of leaf dry weight PM 100% treatment produced maximum value (11.56 g plant -1 ) but at par to other treatments except N 4 followed by N 5 and N 3, respectively (Table 3).

Percentage of marketable roots, smooth roots and forked roots
In case of individual factors, higher marketable roots (84.67%) and smooth surfaced roots (44.89%) were produced by Mino Early Long White and lowest percentage was produced by Pyuthane Red (68.60% and55.36%,respectively) (Table 3).The effect of nutrient sources on marketable root, smooth root and forked root was found insignificant.The interaction effect of varieties and nutrient sources was also found non-significant.
Varietal effects was also found significant in case of harvest index.Mino Early Long White (V 2 ) produced significantly highest harvest index (60.72%)followed by All Season White (57.27%) and Pyuthane Red (51.54%).

Varietal comparison
The varietal comparison of radish was done on the basis of various morphological and sensory characters.The detail comparison is given below.Besides, poultry manure should be used along with inorganic fertilizer with precise calculation of recommended dose of nutrition.Poultry manure alone can produce better results than chemical fertilizer alone.

Table 1 .
Physico-chemical properties of soil sample of the experimental field

Table 2 .
Nutrient content of different organic manures used in the experiment

Table 1 .
Effect of varieties and nut-2016 sources on plant height and number of leaves per plant at 25 DAS and 60 DAS (harvesting) atAFU, Rampur, Chitwan,  2015-2016

Table 2 .
Effect of varieties and nutrient sources on root length, root diameter, root yield, leaf length, leaf width and leaf yield at harvesting at AFU, Rampur, Chitwan, 2015/2016

Table 3 .
Effect of varieties and nutrient sources on root and leaf dry weight, marketable, smooth, forked root percentage and harvest index at AFU, PM = Poultry manure, FYM = Farm yard manure, SEM = Standard error of means, CV = Coefficient of variance